Prior art proposals for building walls of blocks with and without mortar between courses, ties between courses and blocks, and cement poured into the interior exist with many variations, exemplified by those shown in the following U.S. patents.
______________________________________ Patentee Pat. No. Issue Date ______________________________________ Pride 430,810 June 24, 1890 Kidder 742,094 October 20, 1903 McClure 781,344 February 7, 1905 Anderson 802,903 October 24, 1905 Layfield et al 836,589 November 20, 1906 Olafson 1,404,473 January 24, 1922 Odam 2,029,082 January 28, 1936 Pinney 2,228,363 January 14, 1941 Atcheson 2,261,510 November 4, 1941 Jacobson 2,326,361 August 10, 1943 Reichert et al 2,366,572 January 9, 1945 Westveer 2,372,038 March 20, 1945 Johnson et al 2,383,317 August 21, 1945 Adelt 2,821,850 February 4, 1958 Brouk 2,825,221 March 4, 1958 Wilson 2,921,462 January 19, 1960 Wood 3,238,684 March 8, 1966 Kustusch 3,562,991 February 16, 1971 Novoa 3,603,052 September 7, 1971 Frati 3,676,967 July 18, 1972 Wood 3,717,967 February 27, 1973 ______________________________________
However the fact remains that none of these constructions have captured much of the block wall market. It can be postulated that although elements exist which could be abstracted from the prior art to synthesize a construction that would be successful, so far the right combination has eluded those skilled in the art.